In the last few years, the preservation of cultural heritage has become an important issue globally, due to the fact that artifacts and monuments are continually threatened by degradation. It is thus very important to find adequate consolidators that are capable of saving and maintaining the natural aspect of these objects. This study aims to provide an updated survey of the main nanomaterials used for the conservation and restoration of cultural heritage. In the last few years, besides the classic nanomaterials used in this field, such as metal nanoparticles (copper and silver) and metal oxides (zinc and aluminum), hydroxyapatite and carbonated derivatives, tubular nanomaterials (such as carbon nanotubes) have been used as a potential consolidate material of cultural heritage. Tubular nanomaterials have attracted attention for use in different fields due to their structures, as well as their ability to present multiple walls. These nanotubes have the necessary properties in preserving cultural heritage, such as superior mechanical and elastic strength (even higher than steel), high hydrophobicity (with a contact angle up to 140°), optical properties (high photodegradation protection), large specific surface area (from 50 to 1315 m2/g, depending on the number of walls) for absorption of other nanomaterials and relatively good biocompatibility.
Considering that the large quantity of waste electrical and electronic equipment plastics generated annually causes increasing environmental concerns for their recycling and also for preserving of raw material resources, decreasing of energy consumption, or saving the virgin materials used, the present challenge is considered to be the recovery of individual polymers from waste electrical and electronic equipment. This study aims to provide an update of the main identification methods of waste electrical and electronic equipment such as spectroscopic fingerprinting, thermal study, and sample techniques (like identification code and burning test), and the characteristic values in the case of the different analyses of the polymers commonly used in electrical and electronic equipment. Additionally, the quality of the identification is very important, as, depending on this, new materials with suitable properties can be obtained to be used in different industrial applications. The latest research in the field demonstrated that a complete characterization of individual WEEE (Waste Electric and Electronic Equipment) components is important to obtain information on the chemical and physical properties compared to the original polymers and their compounds. The future directions are heading towards reducing the costs by recycling single polymer plastic waste fractions that can replace virgin plastic at a ratio of almost 1:1.
In this study, multi-walled carbon nanotubes (MWCNTs) were decorated with different types of nanoparticles (NPs) in order to obtain hybrid materials with improved antimicrobial activity. Structural and morphological analysis, such as Fourier transformed infrared spectroscopy, Raman spectroscopy, X-ray diffraction, transmission electron microscopy, environmental scanning electron microscopy/energy-dispersive X-ray spectroscopy and the Brunauer–Emmett–Teller technique were used in order to investigate the decoration of the nanotubes with NPs. Analysis of the decorated nanotubes showed a narrow size distribution of NPs, 7–13 nm for the nanotubes decorated with zinc oxide (ZnO) NPs, 15–33 nm for the nanotubes decorated with silver (Ag) NPs and 20–35 nm for the nanotubes decorated with hydroxyapatite (HAp) NPs, respectively. The dispersion in water of the obtained nanomaterials was improved for all the decorated MWCNTs, as revealed by the relative absorbance variation in time of the water-dispersed nanomaterials. The obtained nanomaterials showed a good antimicrobial activity; however, the presence of the NPs on the surface of MWCNTs improved the nanocomposites’ activity. The presence of ZnO and Ag nanoparticles enhanced the antimicrobial properties of the material, in clinically relevant microbial strains. Our data proves that such composite nanomaterials are efficient antimicrobial agents, suitable for the therapy of severe infection and biofilms.
The incidence of colorectal cancer is higher in men than in women, amounting to 15% of cancer-related diseases as a whole. As such, undesirable effects, arising from the administration of current chemotherapeutic agents (the FOLFIRI/FOLFOX combinations), which are exerted on the remaining non-cancerous tissues and/or cells, have contributed to the occurrence of resistance to multiple drugs, thus markedly reducing their efficacy. However, the delivery of chemotherapeutic agents may be improved and their action may be more selectively targeted to diseased tissues/cells by means of developing biotechnologies and nano‑techniques. Thus, the current focus is on creating biological tissue and related tumor models, by means of three‑dimensional (3D) spheres, in an attempt to bridge the gap between results obtained in the pre‑clinical phase and promising outcomes obtained in clinical trials. For this purpose, the characterization and use of so‑called ‘multicellular tumor spheroids’, may prove to be invaluable. In this study, we focus on describing the efficacy of a model 3D system as compared to the traditional 2D tumor spheres in determining drug response, highlighting a potentially greater effect of the drugs following the encapsulation of respective liposomes. The results obtained demonstrate the successful preparation of a suspension of liposomes loaded with folinic acid, oxaliplatin and 5‑fluorouracil (5‑FU), and loaded with meso‑tetra (4‑sulfonatophenyl) porphyrin. Following its use on HT‑29 colorectal cancer cells, an important comparative reduction was noted in the viability of the HT‑29 cells, demonstrating the efficacy of multicellular tumor spheroids carrying liposomes loaded with therapeutic drugs. These findings indicate that the method of drug encapsulation in liposomes may improve the treatment efficacy of chemotherapeutic agents.